Microfacies, Development, and Controlling Factors of Wotuo Coral Reef during the Early Permian in Southern Guizhou

Key words: 
• coral reef /
• Asselian /
• reef community /
• microfacies /
• southern Guizhou

Abstract: [Objective] The Wuotuo village in Zongdi Town, Ziyun County, Southern Guizhou Province, developed an early Permian coral reef that is exposed with a thickness of approximately 45 meters and a lateral exposure of nearly 100 meters. The reef displays a positive relief. [Methods] The methods of paleontology and sedimentary petrology were systematically used to study the Gaozhai coral reef in Zongdi Town, Ziyun County, Guizhou Province. [Results] The fusulinids collected from the reef indicate an Early Asselian age. The primary reef-building organism is identified as the fasciculate colonial coral Fomichevella, while biotic compositions of the coral reef include foraminifers, brachiopods, gastropods, and calcareous algae. The Wotuo coral reef and its underlying and overlying strata contain a broad variety of microfacies types, including bioclastic wackestone-packstone, coral bafflestone, bioclastic packstone, bioclastic grainstone, phylloid algae-cement framestone, fasciculate coral framestone, bioclastic wackestone and foraminifer-fusulinid grainstone. [Conclusion] During the Early Permian, glacial-interglacial cycles were the primary factors influencing the variations in palaeoocean temperature and global sea levels. The vertical microfacies succession in this study provides a record of relative sea-level change. The decline of late Paleozoic glaciation, which resulted in the global warming and a relative rise in sea level, played a pivotal role in the development and flourishing of the coral reefs in southern Guizhou Province.